Research Evidence for the Midwifery Model of Care
Midwifery care is supported by research. Over a period of years, studies examining the outcomes achieved by midwives all over the world have verified the excellent outcomes associated with the midwifery model of care.
The first study known to examine the infant mortality risks for all babies delivered by certified nurse midwives in the United States shows excellent birth outcomes for these midwife-attended deliveries. The study from the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention (CDC) examined all single, vaginal births in the United States delivered at 35-43 weeks of gestation by either physicians or certified nurse midwives in 1991, and is based on information from the death certificate linked to the corresponding birth certificate for each infant under 1 year of age who died in 1991.
After controlling for a wide variety of social and medical risk factors, the risk of experiencing an infant death was 19 percent lower for births attended by certified nurse midwives than for births attended by physicians. The risk of neonatal mortality (an infant death occurring in the first 28 days of life) was 33 percent lower, and the risk of delivering a low birthweight infant was 31 percent lower. Mean birthweight was 37 grams heavier for the certified nurse midwife attended than for the physician attended births. Low birthweight is a major predictor of infant mortality, subsequent disease, or developmental disabilities.
Certified nurse midwives attended a greater proportion of women who are at higher risk for poor birth outcome: African Americans, American Indians, teenagers, unmarried women, and those with less than a high school education. Physicians attended a slightly higher proportion of births with medical complications. However, birth outcomes for certified nurse midwives were better even after sociodemographic and medical risk factors were controlled for in statistical analyses.
The differences in birth outcomes between certified nurse midwife and physician attended births may be explained in part by differences in prenatal, labor, and delivery care practices. Other studies have shown that certified nurse midwives generally spend more time with patients during prenatal visits and put more emphasis on patient counseling and education, and providing emotional support. Most certified nurse midwives are with their patients on a one-on-one basis during the entire labor and delivery process providing patient care and emotional support, in contrast with physician’s care which is more often episodic. Other differences between physician and certified nurse midwife care are discussed in more detail in the article.
MacDorman MF & Singh GK. “Midwifery care, social and medical risk factors and birth outcomes in the USA,” Journal of Epidemiology and Community Health, May 1998.
The Cochrane Collaboration is a systematic review of the research evidence about the effects of care given to women during pregnancy and childbirth. It classifies elements of care as effective, promising, not proven either way, or not worth using. The database is available in printed format as well as in a regularly updated electronic format. Now twenty years old, the Cochrane Database of Systematic Reviews continues to validate the midwifery model of care. For data on specific aspects of care, go to the Cochrane Pregnancy and Childbirth Group Abstracts.
PubMed is the National Library of Medicine’s search service that provides access to over 10 million citations in MEDLINE, PreMEDLINE, and other related databases, with links to participating online journals.
The Maternity Wise website offers the full text of the current edition of A Guide to Effective Care in Pregnancy and Childbirth. Visitors can review the table of contents, chapter outlines, and synopsis chapter (with 6 tables) on html pages, and then download PDFs of any chapters of interest at no charge. This book (which reviews often call the “Bible” of maternity care) was written for all who plan, provide, or receive maternity care, and it is quite accessible to a wide audience. Its entree page is: www.maternitywise.org/guide/
Ingenta.com is an internet service that enables you to access the full-text of your journal subscriptions online and, in addition, gives you the chance to purchase articles from over 26,000 publications on a pay-per-view basis, deliverable by fax or Ariel delivery. Ingenta’s database includes 5,400+ full-text online journals and 26,000 publications.
Birtha is a program for analyzing birth data, including information on different outcomes based on care provider.